BBC: 'When I was at school, the whispered warning Charlie's dead alerted a girl to the fact that her petticoat was showing under her lovat-green school skirt. Horror of horrors!
'There are various theories as to where that curious phrase came from. It seems to date from World War II, and my own favourite explanation is that in the 1940s, the window-blinds were lowered whenever there was a death in the house.
'The dipping half-slip was like a lowered window-shade. More fanciful versions involving Bonny Prince Charlie or Charles II, are, I am afraid, historically implausible, though no doubt a number of listeners will write or e-mail me to say that they prefer them.'